Enhanced CO Selectivity in CO ₂ Electroreduction on Pyrazole‐Modified Boron‐Doped Diamond Electrodes

Electrochemical CO 2 reduction is a promising technology for converting CO 2 into value‐added compounds, contributing toward a sustainable society. Controlling product selectivity is a critical aspect of CO 2 electroreduction, and various approaches have been developed to achieve high efficiency and selectivity. Bulding on our previous findings that surface modification of boron‐doped diamond (BDD) electrodes with aniline enhances the selectivity of CO production through CO 2 capture by the nitrogen lone pair, we herein report pyrazole‐modified BDD electrodes to further improve performance. The potential dependence of product selectivity was investigated, revealing that CO production was prominent at relatively positive potentials. Significantly, the selectivity of CO production was increased by up to a factor of two compared with the previously reported aniline‐modified BDD. This enhanced performance is attributed to the synergistic effect of the adjacent nitrogen atoms: the high nucleophilicity of one nitrogen atom facilitates CO 2 capture, while the adjacent NH moiety stabilizes the intermediate through intramolecular hydrogen bonding.